Apparatus for the production of air foam and air foam fire-extinguishing installations



Dec. 4, 1951 G. CLEMENS ET AL APPARATUS FOR THE PRODUCTION OF AIR FOAMAND AIR FOAM FIRE-EXTINGUISHING INSTALLATIONS 2 SHEETS-SHEET 1 FiledSept. 25, 1950 W. WW t o o r W a Q t s a ee LC WY 0&7 Z twfiw Q... 5 umgq E H w m 3 1951 G. CLEMENS ET AL 2,577,451

APPARATUS FOR THE PRODUCTION OF AIR FOAM AND AIR FOAM FIRE-EXTINGUISHINGINSTALLATIONS Filed Sept. 23, 1950 2 SHEETSSHEET 2 Patented Dec. 4, 1951ABPARAEUSiFQErTHE PRDDUCIIONJ? FOAM AND AIR,- FOAM FlltEzExTlNGlllsfl-INGPINSTALLATIONS Gilnt'er- Clemens, Hamburg-Nienstedten,-= andE'gidiusir. Westenfelder, Germany;.='.assignors:to StanGandgOiLDeYelQm-Jment. Com-pan Elizabeth; Nit-J n Application September 23, 1950;"Seria1'No.- -18Ii,402 In Germany l ebruary zig -1949* In: stationaryairrfoamafire?extinguishin installations -for.--- storage: tanks {for rinflammable liquids; the ,airnfoamahas; tmzbe introduced atthe-:upper-edge of: the-..tanh. 1. Heretofore,--there-: fore; air-foam?producers;simiianrinaform-"to: air; jet pumps whichz-arewfedrwith .gthezmixture of" water and .foamvproducing agent vbyn-meansi ofhorizonaland:-vertical -liquid 1 pipe-.1ines,-: have been: mounted externally -in, thevioinity -of the upper edge of the tank.v lnithislknowmarrangea ment,however, there is a danger that-,thecairfoam producer will be-damagedin: the event "of an-explosiom of. the --tank.'-, for.- example if;the-too oi, the... tank 1 is .sblown off;- Furthermore this. method 10fQ mounting. makesr-suprvision, ofjrthe. air-.foam producer. ,very..diffloult.

Theunderlyin problemwithwhichihe. 111356111. tion. is concerned is .to.pr.ovide... anairfoam..p11o.-- ducing apparatussimilar .in.form. to, anair jet) pump,,in which the air foam is.conveyed .under. its ownpressurepover a,considerab1e distance and/or'a considerable height, andwhichioonsequently may be -mounted on the ground or inthevicinity-thereof In accordance with recent requirements the air foam hasto have a ratioof water to air of from 1:5 to -1':-'10;*and inaddition-possess' adequate stability; which isobtained, for example, bya good water retaining "power.- This problem-cannot be solved withtheair-foamproducers known---heretofore.-- If "an attempt ismade to conveyair-foamoven-considerable-distances with the-known-apparatus;aback-pressure is set up, the-=efiect of 'which' -is that thefoam flowsbackwards out ofthe-air inlet openings of'the-air-jet'pump. Incontradistinction to the existing prejudice -that the problem of"producing and conveying air-foam over--- con-- siderable distances by--means- -01 air -jet' pumps is insoluble; the present inventionisb'ased on the observation that the problem can -be-- solved if-- theair' jet pump is f special design" 'and dimensions; In the knownairetpumpsemployed heretofore,- which: in general" operated fwith -fineatomisation of th'8*--1lqtlidl1?j8li, the"g1 -eat'er .--part": ofthe-*kinetic energy inherentiin the? llquid'jet;

foam mixing, so. that;, after. leavinggthe; foamv producer-,;- the 1actua1'; f'oam ...j et, possesses; only a, small amount of ,kineticienerY-r For :thiSJGaSQR such f0.am..-1z rmiuoi'ng,am aratus is.notradapted.-to. overcome. acQnsiderabIe -.back..pressure-in the supp1y .pipe-line.It is.therefore necessary tot. design, .ands-dimensionathe=foain:prodno71.ngg. an paratus so that the least possible energy'SZJQSZT mthe. suctionx--sanctimixinegworkziofzitheieta.and so rranedrraimiBin-pumps:M 6; s ured o-con Hamburg -Fuhlsbutt'el,

2 consequently sufficient; amounts:- of J energy vare, available,:f.or;;rconveying-;;the foam.

Iii-is; an obj ectof; the ;invention,-.- tom-provide :an. apparatus,for; the productionyof air-.foam which ismonveyed under itSisOWl'ipressure-over; a'-con-.

siderable distance andlomaszconsiderable height, comprising :a.pluralitw, of open; air .jet pumps connectedin parallel which. are fedfrom a com-, 1 mon foantirliql id.pipeeline, andgopen into-"a .com-; monfoam pipeeline the; j QtxIlOZZlQSi rand-mixing; tubes; of the air :jetpumps: being; designed .;and;

dimensioned :in. suchi-a'rmanner that a;jet of good.

coherencei'and.havingdittleatendencxrto scatter.- issues: from he: j t;'nozz 1e,:-.said;.jet: *beinepnarrowlm nolos d sbib'i' mixingrtuber.pre ra ly of; cylindrical shape; whereby-t iti-is maintained overs;

azconsiderable lenethiwi hou premature sbre k:-- in p;-

When:this condition is.=sat-isfie.d, the energylost through} air suctionand. foam-production work z-is reduced .to-a minimum.- 1. It: is clearthat inorder-tmcarrythe. principle i of: the invention intoeffectgthetcrossesection of the mixing'tubemust; be in; at certain-ratioto the crossesectionq of. the jetnozzle. The :ratio of: thecross-sections;-

should beon1y;s1ightly greater than the ratio of.- water; to. air;- thatis-z-tosay, asastated above, from .-.1 2.5. L to 1 10.

A.--further-objeot -oi--: the invention; is, to. provide astationary;air-foam extinguishing installation for storage tanksz-containing-inflammable 1- 1iquids,=. which: is; fed, by an; air-foamvproducing apparatus of thegkindusetzforth. above, the air. foam producinwapparatus.being arranged an or close to the. aground; and 1. preferablyoutside the.- protection rwall, ;and .bei ng ;;connected bymeans;-

of; a.,f.0am -.a scension: pipe.;to ithezfoam inlet, into the.- tank-1 Aform of the inventiomis.illustratedsbyytheg accompanyingdraw-ingsimwhich:

Fig.5 1gshows.=aafoamsproducingg apparatusgaccording to i.thevinvention, in leyatiom.

Fig 2i. shows ga foam. producer, according. to

Fig.1; 1 tinalongitudinah;section:,;in: the direction; ll'e lriinr-Fiei8-5011; a flar er iscalet Figs 3 ashowss a section: ,-inthe-.-i1iection=: 11-1- 1 Fig. 4 shows an air jet pump with internal;

air supplygon aglargermscale;

Figure =5. showsdiagrammaticaliy the -;arrangementiona;foamieiitinguishinguinstallation :on .a

necting pieces 9 on the nozzle plate I of a liquid distributor 8. Theliquid distributor widens conically in the direction of flow and isprovided with fittings for reducing the resistance to flow, for examplein the form of a cone I or streamlined body mounted in the centre of thenozzle plate I with its apex pointing against the direction of flow. Thesupply of water mixed with foaming agent may be connected to the flangeII of the liquid distributor 8. In this case, the flange I I may beconnected directly or indirectly by means of hose-pipes to a mixingpiece, not shown, which in its turn has connections for the water andfoaming agent pipe-lines. The flange II, however, may also be connectedto the water supply, while the foaming agent enters through an inlet [2and is distributed in a-man-v ner not shown. The connecting piece I3 isfor the connection of a pressure gauge.

The air jet pumps I to 6 consist of a liquid nozzle M, which iscylindrical in its forward part. The cylindrical part of the nozzle hasa cylindrical core l5, thus providing a nozzle exit of annularcross-section. This results in a low scatter effect of the liquid jetwhich emerges with a large surface.

As shown in Fig. 4,'the core I of the liquid nozzle I4 may be replacedby a tube I6, through which enters the air supplied from inside to theliquid jet issuing from the annular space H of the nozzle, so thatintimate contact takes place between the hollow cylindrical liquid jetand the air aspirated from the outside and inside. Secured to the nozzleplate I is a tube l8 or similar suitable connecting means, carrying atits other free end a plate l9 having six boreholes in which are mountedthe mixing tubes 20, carrying the air nozzles 2| projecting beyond theedge of the nozzles l4. It is essential that a separate mixing tubeshould be provided for each jet pump, and that the mixing tubes shouldrun substantially parallel or converge at a slight inclination to thecentral axis. At their other ends, opposite to the air nozzles 2|, themixing tubes 20 are fixed in a plate forming the bottom of a foamchamber 22, which gradually tapers to the prescribed connection width ofthe foam pipe-lines or pouring pipes to be connected to the flange 24.As indicated in Fig. 2, a ring 22 may also be used instead of a plate,in which case the plate I9 forms the bottom of the foam chamber. Aconnecting piece 25 is provided for the connection of a pressure gauge.

' Conveniently, the mixing tubes 20 are sur rounded by a conical casing26 with line contact. This casing 26 imparts protection and adequatestrength to the apparatus. Preferably, the casing 26 is constructed sothat it forms at the same time the foam chamber 23.

The operative reliability of the foam producing tubes according to theinvention is substantially greater than that of the known tubes, sincerebounding and reversal of flow do not occur. In addition, considerableresistances in the conveying pipe-line are overcome, such as occur 'forexample with inadequate'liquid pressure in consequence of the formationof excessively heavy foam.

Whereas in the known foam producers, a foam of high conveying pressurehas been possible only with the use of pumps, and the extinguishing of amineral oil tank of large diameter by means of air-foam has. heretoforebeen practically impossible, it is possibleby the present invention forsuch tanks to be rendered safe by foam-producing tubes operating withoutportable pumps. In addition, the foam-producing capacity, that is tosay, the effective quantity of foam produced per foam-producing tube inunit time, is substantially greater than in all the systems knownheretofore. In consequence of the high foam-producing capacity, the goodquality of the foam and the high foam pressure, large tanks filled withmineral oil may be provided with air-foam fire-extinguishinginstallations and fires may thus be extinguished, since it is possibleto provide the foam-producing tubes in a stationary or mobile manner onthe ground and it is not necessary to mount the foam-producing tubes onthe upper edge of the tank as heretofore. This affords the advantagethat, for example, adequate protection may be provided for very largestorage installations with a few mobile foam-producing tubes.

As follows from Fig. 5, in using the foam-producing tubes of theinvention, it is'merely necessary to provide the tanks with anextinguishing pipe network 21 with rising pipes 28, which lead to theupper part of the tank 29. The connecting points 30 for thefoam-producing tubes may be provided in a readily accessible mannerclose to the ground and outside the protection wall 3|. This arrangementpermits of the connection of portable foam-producing tubes at thenecessary connecting points in each case.

We claim:

' 1. Apparatus for the production of air-foam, comprising an elongatedfoam delivery chamber having a discharge end and an inlet end, a foammixing tube extended into said chamber toward the discharge end thereof,terminating in longitudinally spaced relation thereto, injector meansfor introducing foam forming liquid into said tube as an annular streamof such liquid, means for admitting air into said tube as a flowingstream in intimate surface contact with said annular stream of liquid,and conduit means for supplying foam forming liquid to said injectormeans.

2. Apparatus according to claim 1, in which said injector meanscomprises a jet nozzle member having a discharge end and a coaxial coreelement interiorly of said end, said element in radially spaced relationto said nozzle forming an annular discharge passageway.

3. An apparatus according to claim 2, in which said core element is asolid cylindrical element.

4. An apparatus according to claim 2, in which said core element is ahollow tubular pipe element opening at one end through the nozzledischarge end, the other end of said element opening outwardly through aside wall of said nozzle.

5. Apparatus for the production of air foam, comprising a foam chamber,having inlet and outlet ends respectively, a plurality of foam mixingtubes, each having an inlet end and a discharge end, extended into saidchamber through the chamber inlet and disposed axiallythereof incircularly spaced relationone to another,--ex-- tending in the directionof the chamber outlet,

withthe discharge ends terminating interiorly of the chamber insubstantially equidistant spaced relationv to the outlet end thereof andthe inlet ends opening outwardly therefrom, and conduit means forinjecting foam-forming liquids into the inlet end of each foam-mixingtube as a jetted annular stream of such liquids and so as to inspirateair through said mixing tube inlet ends. I I 6; An apparatus-accordingto claim 5, in which said foam-forming chamber comprises an elongatedcasing member having a foam outlet end and a closure member for theopposite end of said casing and chamber, said member providing supportmeans for the mixing tubes extended into said chamber.

7. An apparatus according to claim 5, in which said axially disposedmixing tubes extend in substantially parallel relation to each other andto the principal axis of said chamber through the outlet thereof.

8. An apparatus according to claim 5, in which said axially disposedmixing tubes extend longitudinally of said chamber in convergingsubstantially uniformly angular relation to the principal axis of saidchamber through the outlet thereof.

9. An apparatus according to claim 5, in which said conduit means forinjecting foam-forming liquids into the inlet end of each foam mixingtube, comprises a conduit distributor element having an inlet portion,and an outlet end portion extended toward and terminating in spacedrelation to the inlet ends of said mixing tubes, and a plurality of jetnozzle elements for discharge of said liquids, each having an inlet endcommunicating with said distributor element and a discharge end extendedinto the inlet end of a mixing tube in radially spaced relation to saidtube.

10. An apparatus according to claim 9, in which said distributor elementcomprises a hollow, frusto-conical member having an inlet at the apexend thereof and an open base end portion. a closure plate for said baseend portion, and a plurality of tubular conduit members supported by andopening through said closure, each of said members adapted to receiveand communicate with a jet nozzle element for discharge of foam-formingliquids therethrough.

11. An apparatus according to claim 9, in which said distributor elementcomprises a conduit member flared outwardly in the direction of saidmixing tube inlets providing a chambered portion in said member.

12. An apparatus according to claim '10 including a flow deflectorinternally of said distributor element and comprising a conical membersecured to said closure plate by its base end and concentricallytherewith, the apex end of said member extending in the direction of theinlet to said distributor element.

13. Apparatus for the production of air-foam which comprises thecombination of a casing defining a foam chamber, said casing havingopposite inlet and outlet portions, a closure for the inlet end portionof said casing, said closure provided with a plurality of radiallydisposed, circumferentially spaced passageways opening therethrough intosaid casing, a plurality of foam-mixing tubes extended through saidpassageways into the casing and chamber, said tubes each having an inletend opening exteriorly of the casing and discharge end opening into thecasing and chamber, said tubes supported within said casing in spacedrelation to one another circumferentially of the chamber, and arrangedtherein with the axis of each tube in substantially equidistant radialrelation to the axis of said casing, and means for supplyingfoam-forming liquids and air to said mixing tubes, comprising conduitmeans for conveying said liquid, a liquid distributor membercommunicating with said conduit means at one end and flared outwardlytherefrom toward the inlet end of said casing, a plurality of jet nozzleelements opening from said distributor member and extending therefrominto the inlet ends of said mixing tubes in coaxial radially spacedrelation thereto, and a concentric core element internally of each jetnozzle providing for the discharge of an annular liquid streamtherefrom.

GUN'I'ER. CLEMENS.

EGIDIUS WESTENFELDER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,629,027 Erwin May 17, 19272,073,204 Friedrich Mar. 9, 1937 2,164,153 Friedrich June 27, 19392,423,618 Ratzer July 18, 1947

